Re: [libvirt] [PATCH 5/5]virsh: mark '--shareable' as VSH_OFLAG_IGNORE

-----Original Message----- From: Eric Blake [mailto:eblake@redhat.com] Sent: Tuesday, October 22, 2013 2:23 PM To: Chen Hanxiao; 'Michal Privoznik' Cc: libvir-list(a)redhat.com Subject: Re: [libvirt] [PATCH 5/5]virsh: mark '--shareable' as VSH_OFLAG_IGNORE On 10/22/2013 07:13 AM, Chen Hanxiao wrote: >>> >> >> Wow, we've never wanted to hide any option before? I've recall >> introducing VSH_OT_ALIAS, but there hasn't been anything else? We've always hidden one spelling that duplicates another, but this is a case where a boolean option is a duplicate of a non-boolean option, so I'm not sure if VSH_OT_ALIAS alone does what we want (or maybe it just means we enhance VSH_OT_ALIAS to be able to express a boolean alias for a non-boolean default). > > Do you mean we just treat --shareable as an alias for --mode like this: > > {.name = "shareable", > - .type = VSH_OT_BOOL, > + .type = VSH_OT_ALIAS, > - .help = N_("shareable between domains") > + .help = "mode" If it works. Maybe even by having it be an alias for .help = "mode=shareable" rather than just "mode", and teach VSH_OT_ALIAS to handle '=' within the .help text.

> }, > > But with VSH_OT_ALIAS, auto complete could also get it. Command line completion is orthogonal. It needs fixing anyways (there were patches posted last month, but I haven't seen any recent action on them). Ideally, we want the following: attach-disk <TAB> to NOT show --shareable (because it can show --mode instead) attach-disk --sh <TAB> would show --shareable (just because it's deprecated and hidden by default does NOT mean it must be hidden if the user explicitly requests something that can't complete in any other way) attach-disk --mode=shareable --sh<TAB> attach-disk --mode readonly --sh<TAB> would both complain about no possible completion (because --shareable has already been eliminated by --mode appearing earlier). attach-disk --shareable --mo<TAB> would complain about no possible completion (--shareable implies --mode=shareable, and --mode can't appear more than once). But getting that working in this patch series is NOT a prerequisite - save it for everything else that needs fixing with completion.

> We still need new flag to hide it. I'm still not convinced we need VSH_OFLAG_IGNORE. VSH_OT_ALIAS, plus new logic that lets a boolean be an alias to non-bool=value, ought to be the way to do it (ie. fix our existing aliasing mechanism, rather than adding a second aliasing mechanism).

-- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org